Tow-diverting chute for depositing running tow on a conveyor belt



Feb. 7, 1% w. H. SPRUILL 3,392,839

TOW-DIVERTING CHUTE FOR DEPOSITING RUNNING TOW ON A CONVEYOR BELT FiledMarch 25, 1.965

INVENTOR WILLIAM HAMPTON SPRUILL ATTORNEY United States Patent 3,302,839TOW-DIVERTING CHUTE FOR DEPOSITWG RUNNiNG TOW ON A (IQNVEYUR BELTWilliam Hampton Spruill, Kinston, N.C., assignor to E. I.

du Pont de Nemours and Company, Wilmington, Dek,

a corporation of Delaware Filed Mar. 25, 1965, Ser. No. 442,590 3Claims. (Cl. 226-196) This invention relates to tow delivery apparatusfor depositing on a surface in a sinuous pattern a running length ofyarn or tow composed of a plurality of filaments. It is moreparticularly concerned with a tow-diverting chute for use in suchapparatus to deliver running lengths of tow at high speeds totow-receiving means, which may be a conveyor belt or shipping containersused for forming large packages of tow from which tow lengths arereadily removed.

In the handling of yarns or tows on the run, difficulty is usuallyencountered in static generation, filament or yarn breakage, wrapformation, tension variation, snagging, and the like. When a largenumber of yarn ends are being run simultaneously, these difliculties areespecially serious and must be avoided. Many devices and apparatus havebeen described to overcome or avoid specific problems occurring,particularly in the processing of a tow composed of a large number offilaments, which deal with a driving device for the tow or forcontrolling the laydown pattern of the tow on a conveyor in order tofacilitate drying of the tow. All of these devices have successfullyovercome the problems for which they were intended but they have been oflittle assistance in overcoming the prob lems of snagging of a few ofthe filaments of the tow bundle in the laydown chute. It is especiallyimportant to overcome this problem in delivery mechanisms used for highstrength synthetic fibers, Where a few filaments snagged in the chutewill support a heavy tow. When snagging occurs, subsequently deliveredtow will bunch and plug the chute or accumulate until there issufficient tow weight to break or pull the snagged filaments free,causing erratic delivery and poor quality. High-speed operationmultiplies this difiiculty because such interruptions will form quicklyand grow to serious proportions before an operator can shut down theequipment.

An object of this invention is to provide an apparatus for diverting atraveling tow to a position at which the tow is to be laid down .on aconveyor for additional processing steps such as washing or drying.Another object is the provision of an apparatus for the snag-free,consolidated discharge of a tow into a sinuous pattern .on a conveyorbelt or into a package. Other objects will appear hereinafter.

In the drawing, which illustrates an embodiment of the invention,

FIGURE 1 is an isometric projection of the chute, and

FIGURE 2 is a schematic view of apparatus utilizing the chute of FIGURE1.

Referring to FIGURE 1, the chute 1 is formed of wire cloth, preferably 8x 8 mesh (3.15 x 3.15 mesh per centimeter), of 0.033-inch diameter(0.838 mm.) stainless steel wire supported by a frame 2 which issuitably attached to the edge of the wire cloth by polished joints ofbrazing, welding or the like. The frame 2 includes at least an upperyoke 3 and a lower yoke 4, which are attached to a rod 5 and brace 6.Stub shafts 7 are attached to the upper yoke 3 to provide a pivotalmeans of support in bearings. The chute is smoothly curved through anarc of about 60 and tapers from the top to the bottom of the chute todivert and consolidate the tow to be deposited.

FIGURE 2 shows the above chute positioned in a tow delivery apparatus ofa type which is conventional in other respects. As illustrated, the towdescends approximately 3,302,339 Patented Feb. 7, 1967 vertically intothe entrance of the pivotally-mounted c'hute 1 of wire cloth. The tow isconsolidated by the converging wire cloth walls of the chute, divertedto a near horizontal direction by the curvature of the chute, anddischarged from the mouth of the chute onto a moving conveyor belt orinto a suitable container. Oscillation of the chute about the pivotalsupport by conventional means causes the tow to be laid down on theconveyor belt in a sinuous pattern which is dependent on the frequencyand amplitude of oscillation of the chute.

The chute is useful for directing the path of a moving tow bundle ofsynthetic filaments which have been crimped or of filaments which areuncrirnped. The chute of this invention is particularly useful inapparatus for handling a wet tow of uncrirnped filaments. In suchapparatus, smooth-surfaced sheet metal funnels or chutes have been foundto produce considerable surface friction between the moving tow bundleand the surface of the chute. Particularly, in handling tow whichcarries a sticky or gummy finish, friction .on this smooth surface issufficient to snag, separate, and break individual filaments. Manyattempts to reduce the surface frictional characteristics of the chutehave proven to be unsatisfactory. These attempts have includedantifrictional coatings on the surface of the chute, such as coatings ofsilicones or fluorocarbon polymers, or by the use of matte finishes orother roughened surfaces to reduce the total area of contact between thesheet and the filamentary tow surface. It was indeed surprising,therefore, to discover that the simple use of wire cloth as the surfaceof the chute was sufficient to reduce the frictional drag of the chuteon the tow surface to the point that snagging was eliminated. Inaddition, the use of wire cloth provides for the separation of excessiveamounts of finishes carried on the tow bundle. This may possibly explainwhy the use of wire cloth chutes so successfully eliminate the snaggingconditions, whereas attempts to use matte finish surfaces to reducefrictional characteristics were unsuccessful.

In general configuration, the chute of this invention is similar tochutes of the prior art. Bends and joints should be made as smooth aspossible, and the welded joints of the wire to the frame must be groundand polished. The size and shape of the chute depends upon the size andcomposition of the tow. As an example, in handling a heavy denier tow ofabout 600,000 denier, a satisfactory chute is tapered from about 9inches (24 cm.) in width at the top to about 4 inches (10 cm.) in widthat its mouth. This chute is positioned approximately 15 from thevertical at its entrance and so as to discharge at an angle ofapproximately 15 from the horizontal. The curvature of the chute may bea continuous curve approaching that of a section of a catenary or mayconsist of a straight section which proceeds smoothly into a circulararc of a circle of about 18 inches radius. The chute may be formed ofany suitable metallic stiff wire cloth, although an 8 X 8 mesh (3.15 x3.15 mesh per cm.) stainless steel wire cloth having wires of 0.033 inch(0.838 mm.) in diameter has been found to be particularly suitable.Other materials suitable for use in constructing the chute includeexpanded metal sheeting or perforated metal sheeting which havewell-rounded edges. The over-all length of the chute is preferably about37 inches (94 cm.), but any length between 30 and 40 inches and cm.) isgenerally satisfactory.

The chute of this invention operates satisfactorily in handling yarntraveling at high speeds such as 1,200 yards per minute (1100 meters perminute) and above, although it is also quite useful at the low speedsfrom 100 to 400 yards per minute (.91 to 360 meters per minute) whichare often used. The upper limit on operating speed depends in part onthe yarn finish and the presence or absence of crimp in the tow bundle.Thus sticky or gummy 3 finish requires a lower maximum operating speedthan does uncrimped or low crimp tow. The chute may be used for lowdenier yarns, for example, 680 denier yarns or smaller. It hasparticular utility in the high speed packaging or delivery of heavydenier tow such as 600,000 denier and above.

The improved apparatus of this invention is useful in handling runningyarn ends or tows of any material, synthetic or natural. 'It isparticularly useful in staple production.

It will be apparent that many widely different embodiments of thisinvention may be made without departing from the spirit and scopethereof, and therefore it is not intended to be limited except asindicated in the appended claims.

I claim:

1. In a tow delivery apparatus for depositing a running length of tow ona conveyor belt in a sinuous pattern, the improvement of a wire clothtow-diverting chute for delivering the tow to said conveyor belt withoutsnagging, the wire cloth surface of the chute being smoothly curved todivert the running length of tow through an arc of about 60, taperedfrom about 9 inches in Width at the top to about 4 inches in width atthe mouth to consolidate the tow between converging wire cloth walls asthe tow passes References Cited by the Examiner UNITED STATES PATENTS2,363,219 11/ 1944- Adamson 1932 2,523,558 9/1950 Cavalier l932 X2,722,729 11/ 1955 Wilhelm 2821 2,922,196 l/l960 Kunz et 211.

References Cited by the Applicant UNITED STATES PATENTS 2,468,843 5/1949 Nash.

2,598,000 5/1952 Knopp et al. 2,878,547 3/ 1959 McMaster et al. 3,104,790 9/1963 De Haven.

M. HENSON WOOD, JR., Primary Examiner.

J. N. ERLICH, Assistant Examiner.

1. IN A TOW DELIVERY APPARATUS FOR DEPOSITING A RUNNING LENGTH OF TOW ONA CONVEYOR BELT IN A SINUOUS PATTERN, THE IMPROVEMENT OF A WIRE CLOTHTOW-DIVERTING CHUTE FOR DELIVERING THE TOW TO SAID CONVEYOR BELT WITHOUTSNAGGING, THE WIRE CLOTH SURFACE OF THE CHUTE BEING SMOOTHLY CURVED TODIVERT THE RUNNING LENGTH OF TOW THROUGH AN ARC OF ABOUT 60*, TAPEREDFROM ABOUT 9 INCHES IN WIDTH AT THE TOP TO ABOUT 4 INCHES IN WIDTH ATTHE MOUTH TO CONSOLIDATE THE TOW BETWEEN CONVERGING WIRE CLOTH WALLS ASTHE TOW PASSES THROUGH THE CHUTE, AND OF AN OVER-ALL LENGTH BETWEEN 30AND 40 INCHES.